This study will examine retrograde axoplasmic transport to the visual system, using biochemical techniques and light and electron microscopic cytochemistry. Complexes of antiviral drugs (IDU initially) and proteins (horseradish peroxidase initially) will be prepared and tested for retrograde transport and biological fate in axons of ganglion cells of the sensory trigeminal ganglion which innervate the rabbit cornea. Animals with latent herpes simplex residing in this ganglion will then be evaluated for possible efficacy of introducing the drugs by this route in an attempt to eradicate the latent virus which causes recurrent herpetic keratitis. Studies will be continued on new features of the metabolism of cone outer segments which may facilitate the isolation and characterization of cone visual pigments, which will be important as a foundation for understanding alterations which may occur in cones in retinal diseases.